We can create strings by putting placeholders in string templates, and then substituting values for those placeholders. Here is an example:
"I got %d in %s. I feel %s about that!" % (95, "Linear Algebra", "great")
95 got substituted for %d, "Linear Algebra" got substituted for the first "s", and "great" got substituted for the second %s.
%d stands for "decimal." It must be substituted with an int.
%s stands for "string." It must be substituted with a string.
%f stands for "float." It must be substituted with a float.
The placeholders get substituted by the arguments supplied to the right, in order